#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <cstdio>
#include <ctime>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>
#include <iostream>
#include <algorithm>
#include <functional>
#include <numeric>
#include <string>

#define N_MAX 100

using namespace std;

int main(void)
{
    long long N, D, T, X[N_MAX];
    cin >> N >> D >> T;
    for (int i = 0; i < N; i++) {
        cin >> X[i];
    }
    bool *used = new bool[N]();
    long long ret = 0;
    for (int i = 0; i < N; i++) {
        if (!used[i]) {
            vector<long long> v;
            for (int j = i; j < N; j++) {
                if ((X[i] - X[j]) % D == 0) {
                    v.push_back((X[j] - (X[i] % D)) / D);
                    used[j] = true;
                }
            }
            sort(v.begin(), v.end());
            ret += (v[v.size() - 1] + T) - (v[0] - T) + 1;
            for (int j = 0; j < v.size() - 1; j++) {
                ret -= max(0LL, (v[j + 1] - T) - (v[j] + T) - 1);
            }
        }
    }
    printf("%lld\n", ret);
    return 0;
}